Peculiar Relics from Primordial Black Holes in the Inflationary Paradigm

Depending on various assumptions on the energy scale of inflation and assuming a primordial power spectrum of a Broken Scale Invariance (BSI) type, we explore the possibility for Primordial Black Holes (PBH) and Planck relics to contribute substantially to cold dark matter in the Universe. A recently proposed possibility to produce planck relics in 4-dimensional string gravity is considered. Possible experimental detection through gravitational waves is further explored. We stress that inflation with a low energy scale, and also possibly when Planck relics are produced, leads unavoidably to relics originating from PBHs that are not effectively classical during their formation, rendering the usual formalism inadequate for them.